<?php
/////	PHP CAPTCHA		\\\\\
if(!isset($_SESSION)) {
	session_start();
}

/////	VARS	\\\\\
$CAPTCHA_SESSION_ID			= "php_captcha";
$CAPTCHA_WIDTH				= 200;
$CAPTCHA_HEIGHT				= 60;
$CAPTCHA_NUM_CHARS			= 5;
$CAPTCHA_NUM_LINES			= 60;
$CAPTCHA_CHAR_SHADOW		= false;
$CAPTCHA_OWNER_TEXT			= "";
$CAPTCHA_CHAR_SET			= "A,B,C,D,E,F,G,H,I,J,K,L,M,N,P,Q,R,S,T,U,V,W,X,Y,Z,1,2,3,4,5,6,7,8,9";
$CAPTCHA_CASE_INSENSITIVE	= true;
$CAPTCHA_BACKGROUND_IMAGES	= "";
$CAPTCHA_MIN_FONT_SIZE		= 16;
$CAPTCHA_MAX_FONT_SIZE		= 25;
$CAPTCHA_USE_COLOUR			= false;
$CAPTCHA_FILE_TYPE			= "png";

function CreateCaptcha() {
	global $CAPTCHA_SESSION_ID, $CAPTCHA_WIDTH, $CAPTCHA_HEIGHT, $CAPTCHA_NUM_CHARS, $CAPTCHA_NUM_LINES, $CAPTCHA_CHAR_SHADOW, $CAPTCHA_OWNER_TEXT, $CAPTCHA_CHAR_SET, $CAPTCHA_CASE_INSENSITIVE, $CAPTCHA_BACKGROUND_IMAGES, $CAPTCHA_MIN_FONT_SIZE, $CAPTCHA_MAX_FONT_SIZE, $CAPTCHA_USE_COLOUR, $CAPTCHA_FILE_TYPE, $aFonts;

	if (!function_exists("imagecreate") || !function_exists("image". $CAPTCHA_FILE_TYPE) || ($CAPTCHA_BACKGROUND_IMAGES != "" && !function_exists("imagecreatetruecolor"))) {
		return false;
	}

	$iWidth		= $CAPTCHA_WIDTH;
	$iHeight	= $CAPTCHA_HEIGHT;
	if ($iWidth > 500) {
		$iWidth		= 500;
	}
	if ($iHeight > 200) {
		$iHeight		= 200;
	}

	if (is_array($CAPTCHA_BACKGROUND_IMAGES) || $CAPTCHA_BACKGROUND_IMAGES != "") {
		$oImage	= imagecreatetruecolor($iWidth, $iHeight);

		if (is_array($CAPTCHA_BACKGROUND_IMAGES)) {
			$iRandImage			= array_rand($CAPTCHA_BACKGROUND_IMAGES);
			$oBackgroundImage	= imagecreatefromjpeg($CAPTCHA_BACKGROUND_IMAGES[$iRandImage]);
		} else {
			$oBackgroundImage	= imagecreatefromjpeg($CAPTCHA_BACKGROUND_IMAGES);
		}

		imagecopy($oImage, $oBackgroundImage, 0, 0, 0, 0, $iWidth, $iHeight);
		imagedestroy($oBackgroundImage);
	} else {
		$oImage = imagecreate($iWidth, $iHeight);
	}

	imagecolorallocatealpha($oImage, 255, 255, 255, 127);

	if ($CAPTCHA_OWNER_TEXT != "") {
		$iBlack				= imagecolorallocate($oImage, 0, 0, 0);
		$iOwnerTextHeight	= imagefontheight(2);
		$iLineHeight		= $iHeight - $iOwnerTextHeight - 4;

		imageline($oImage, 0, $iLineHeight, $iWidth, $iLineHeight, $iBlack);

		imagestring($oImage, 2, 3, $iHeight - $iOwnerTextHeight - 3, $CAPTCHA_OWNER_TEXT, $iBlack);

		$iHeight			= $iHeight - $iOwnerTextHeight - 5;
	}

	if (!is_array($CAPTCHA_BACKGROUND_IMAGES) && $CAPTCHA_BACKGROUND_IMAGES == "") {
		for ($i = 0; $i < $CAPTCHA_NUM_LINES; $i++) {
			if ($CAPTCHA_USE_COLOUR) {
				$iLineColour	= imagecolorallocate($oImage, rand(100, 250), rand(100, 250), rand(100, 250));
			} else {
				$iRandColour	= rand(100, 250);
				$iLineColour	= imagecolorallocate($oImage, $iRandColour, $iRandColour, $iRandColour);
			}

			imageline($oImage, rand(0, $iWidth), rand(0, $iHeight), rand(0, $iWidth), rand(0, $iHeight), $iLineColour);
		}
	}

	if (!is_array($CAPTCHA_CHAR_SET)) {
		if ($CAPTCHA_CHAR_SET != "") {
			$aCharSet			= explode(",", $CAPTCHA_CHAR_SET);
			$CAPTCHA_CHAR_SET	= array();

			foreach ($aCharSet as $sCurrentItem) {
				if (strlen($sCurrentItem) == 3) {
					$aRange	= explode("-", $sCurrentItem);
					if (count($aRange) == 2 && $aRange[0] < $aRange[1]) {
						$aRange	= range($aRange[0], $aRange[1]);
						$CAPTCHA_CHAR_SET = array_merge($CAPTCHA_CHAR_SET, $aRange);
					}
				} else {
					$CAPTCHA_CHAR_SET[] = $sCurrentItem;
				}
			}
		}
	}

	$sCode	= "";
	for ($i = 0; $i < $CAPTCHA_NUM_CHARS; $i++) {
		if (count($CAPTCHA_CHAR_SET) > 0) {
			$sCode	.= $CAPTCHA_CHAR_SET[array_rand($CAPTCHA_CHAR_SET)];
		} else {
			$sCode	.= chr(rand(65, 90));
		}
	}
	if ($CAPTCHA_CASE_INSENSITIVE == true) {
		$_SESSION[$CAPTCHA_SESSION_ID]	= strtoupper($sCode);
	} else {
		$_SESSION[$CAPTCHA_SESSION_ID]	= $sCode;
	}

	for ($i = 0; $i < strlen($sCode); $i++) {
		$sCurrentFont	= $aFonts[array_rand($aFonts)];

		if ($CAPTCHA_USE_COLOUR == true) {
			$iTextColour	= imagecolorallocate($oImage, rand(0, 100), rand(0, 100), rand(0, 100));

			if ($CAPTCHA_CHAR_SHADOW == true) {
				$iShadowColour	= imagecolorallocate($oImage, rand(0, 100), rand(0, 100), rand(0, 100));
			}
		} else {
			$iRandColour	= rand(0, 100);
			$iTextColour	= imagecolorallocate($oImage, $iRandColour, $iRandColour, $iRandColour);

			if ($CAPTCHA_CHAR_SHADOW == true) {
				$iRandColour	= rand(0, 100);
				$iShadowColour	= imagecolorallocate($oImage, $iRandColour, $iRandColour, $iRandColour);
			}
		}

		$iSpacing		= (int)($iWidth / $CAPTCHA_NUM_CHARS);
		$iFontSize		= rand($CAPTCHA_MIN_FONT_SIZE, $CAPTCHA_MAX_FONT_SIZE);
		$iAngle			= rand(-30, 30);
		$aCharDetails	= imageftbbox($iFontSize, $iAngle, $sCurrentFont, $sCode[$i], array());

		$iX				= $iSpacing / 4 + $i * $iSpacing;
		$iCharHeight	= $aCharDetails[2] - $aCharDetails[5];
		$iY				= $iHeight / 2 + $iCharHeight / 4; 

		imagefttext($oImage, $iFontSize, $iAngle, $iX, $iY, $iTextColour, $sCurrentFont, $sCode[$i], array());

		if ($CAPTCHA_CHAR_SHADOW == true) {
			$iOffsetAngle	= rand(-30, 30);
			$iRandOffsetX	= rand(-5, 5);
			$iRandOffsetY	= rand(-5, 5);

			imagefttext($oImage, $iFontSize, $iOffsetAngle, $iX + $iRandOffsetX, $iY + $iRandOffsetY, $iShadowColour, $sCurrentFont, $sCode[$i], array());
		}
	}

	if (in_array($CAPTCHA_FILE_TYPE, array("gif", "png", "jpeg"))) {
		$sFileType = $CAPTCHA_FILE_TYPE;
	} else {
		$sFileType = "jpeg";
	}

	header("Content-type: image/$sFileType");

	if ($sFileType == "gif") {
		imagegif($oImage);
	} elseif ($sFileType == "png") {
		imagepng($oImage);
	} else {
		imagejpeg($oImage);
	}

	imagedestroy($oImage);

	return true;

}

function ValidateCaptcha($sUserCode, $bCaseInsensitive = true) {
	global $CAPTCHA_SESSION_ID;
	if ($bCaseInsensitive == true) {
		$sUserCode	= strtoupper($sUserCode);
	}

	if (!empty($_SESSION[$CAPTCHA_SESSION_ID]) && $sUserCode == $_SESSION[$CAPTCHA_SESSION_ID]) {
		unset($_SESSION[$CAPTCHA_SESSION_ID]);
		return true;
	}
	return false;
}